Inkjet technology has expanded its application to high-speed, commercial and industrial printing, in addition to home and office usage, because of its ability to produce economical, high quality, multi-colored prints. This technology is a non-impact printing method in which an electronic signal controls and directs droplets or a stream of ink that can be deposited on a wide variety of media substrates. These printable media or recording material can be cut sized sheets or commercial large format media such as banners and wallpapers. Current inkjet printing technology involves forcing the ink drops through small nozzles by thermal ejection, piezoelectric pressure or oscillation, onto the surface of such media. Within the printing method, the media substrate plays a key role in the overall image quality and permanence of the printed images.
Nowadays, there is a growing demand for digitally printed contents which is no longer limited to the “traditional” black-white text images and full color photo images, but extends also to prints with visual special effects such as the metallic appearance and/or reflectivity, for example. Accordingly, investigations continue into developing media and/or printing methods that can be effectively used with such printing techniques, which imparts good image quality and which allow the production of specific appearances.
Some printing media may contain substances which over time may migrate to the printing surface. This phenomenon may occur for instance when rolled media is exposed to high temperatures, for example, during transportation or storage, or simply when media is stored for some time before use.
For example, print media such as vinyl and PVC banners may contain plasticizers to increase their flexibility, and these additives may tend to migrate to the surface as non-uniform exudates. Other substances that may exhibit a tendency to migrate to the printing surface may be, for example, adhesives or silicones present in adhesive media.